A semiconductor circuit or logic device may be designed for any of a variety of applications. Typically, the device includes logic circuitry to receive, manipulate and/or store data at an input terminal of the device, and the same or modified data is subsequently generated at an output terminal of the device.
Such devices are typically formed as an integrated circuit (IC) which has one or more commonly used internal operating voltages used by the various elements of the IC. An external source power signal (Vcc) is typically supplied to a power pin of the IC. This Vcc signal is then used to supply power to the circuits internal to the IC. The voltage of the Vcc signal may be reduced to a level appropriate for the circuit as an internal voltage (Vcci). Sometime near the end of the IC manufacturing process, the IC is run through at least one test to verify at least a basic level of conformity to the specifications for the IC. These tests typically involve application of various types of signals using test probes, at the IC's input/output pins.
Conventionally, test circuits are designed into the IC to facilitate an expedited testing process. Previously used test circuits, however, are relatively complex and require that multiple test signals be applied to multiple input pins of the IC.
In connection with the present invention, it has been discovered that such an IC can be designed to provide a stream-lined testing of the IC generally and to validate the IC's processing of one or more of its internal signals.